Climate by Place

San Antonio, TX climate: monthly averages and frost dates

San Antonio, TX has mild winters and hot summers by this site's scale, with moderate annual precipitation. The figures are the 1991–2020 climate normals for NOAA station USW00012921 (SAN ANTONIO INTL AP), 6 mi (10 km) in a straight line from the city's center point (US Census).

Warmest month high
96.0°F
August
Coldest month mean
52.2°F
January
Precipitation
32.4 in
per year
Snowfall
0.2 in
per year
Median last frost
February 26
32°F, spring
Median first frost
November 28
32°F, autumn

Monthly averages in San Antonio

San Antonio, TX: normal high, low and precipitation by month Normal daily high and low by month and monthly precipitation for San Antonio, TX. Highs peak in August at 96.0°F; the wettest month is May at 4.40 in. 40°F 60°F 80°F 100°F 63 68 74 80 87 92 95 96 90 82 72 65 41 45 52 58 66 73 75 75 70 60 50 42 5 in 2.0 1.7 2.3 2.4 4.4 3.3 2.4 2.1 3.9 3.8 2.1 2.0 J F M A M J J A S O N D Normal daily high Normal daily low Precipitation (in)
NOAA 1991–2020 monthly normals, station USW00012921. “–” means NOAA publishes no value.
MonthHigh °FLow °FMean °FPrecip. inSnow inDays ≥0.01 inDays ≥90°FNights ≤32°F
January 63.341.052.21.960.0 6.90.04.7
February 67.545.156.31.740.1 7.40.22.7
March 73.851.862.82.310.0 8.50.51.0
April 80.358.469.42.420.0 6.43.20.0
May 86.666.476.54.400.0 8.311.80.0
June 92.472.782.63.280.0 7.024.00.0
July 94.974.784.82.410.0 5.028.50.0
August 96.074.985.52.150.0 4.728.80.0
September 90.169.679.93.880.0 6.919.70.0
October 82.260.471.33.750.0 6.45.60.0
November 71.749.860.72.080.0 6.40.11.3
December 64.742.453.52.000.1 7.40.04.3
Year 80.358.969.632.380.2 81.3122.414.0

How cold is winter in San Antonio?

Winters in San Antonio are mild by this site's scale (coldest-month mean 45 to under 60°F). The coldest month is January, with a mean temperature of 52.2°F (11.2°C), a normal daily high of 63.3°F (17.4°C) and a normal daily low of 41.0°F (5.0°C).

The station averages 14.0 nights a year at or below 32°F and 0.2 days when the high stays at or below 32°F.

How hot is summer in San Antonio?

Summers in San Antonio are hot by this site's scale (hottest-month high 90 to under 100°F). August has the highest normal daily high, 96.0°F (35.6°C), with nights averaging 74.9°F (23.8°C).

The high reaches 90°F or more on 122.4 days in a normal year.

The normal daily high itself is 90°F or above in June to September.

What is the wettest month in San Antonio?

San Antonio gets 32.38 in (822 mm) of precipitation in a normal year, which this site classes as moderate (20 to under 40 in a year). The wettest month is May with 4.40 in (112 mm); the driest is February with 1.74 in (44 mm).

Measurable precipitation (0.01 in or more) falls on 81.3 days a year.

Does it snow in San Antonio?

Snow is rare in San Antonio: the normal annual snowfall is 0.2 in (1 cm).

Which months are mild in San Antonio?

5 months in San Antonio meet this site's comfort thresholds (normal high 65–85°F, low 45°F or higher, fewer than 10 days with 0.10 in or more of precipitation): February to April, October and November.

Thresholds and their limits: methodology.

Frost dates and growing season in San Antonio

In San Antonio the median last spring night at or below 32°F is February 26, and the median first autumn one is November 28 (NOAA P50 dates). NOAA's median length of the freeze-free season is 277 days. NOAA takes that median over each year's own season, so it need not equal the 275 days between the two median dates.

There is still a 10% chance of a 32°F night on or after March 17, and a 10% chance that the first one has come by November 7.

The chance that the last spring 32°F night comes on or after January 29 is 90%.

For a hard freeze (28°F or lower) the median dates are February 9 in spring and December 13 in autumn.

32°F frost dates by probability (NOAA PRBLST, PRBFST, PRBGSL). The 50% row is the median. Season lengths are NOAA’s own percentiles of each year’s season, so they need not equal the gap between the two dates in the same row.
ChanceLast spring 32°F night on or afterFirst autumn 32°F night byFreeze-free season, days
10%March 17November 7311
20%March 10November 15298
30%March 6November 20289
40%March 2November 24283
50%February 26November 28277
60%February 21December 1271
70%February 16December 6264
80%February 8December 11257
90%January 29December 22247
Median (P50) dates at each temperature threshold NOAA publishes.
ThresholdMedian last date (spring)Median first date (autumn or winter)Median season, days
36°F March 10November 16251
32°F February 26November 28277
28°F February 9December 13311
24°F January 22January 1352
20°F No such night in most years, though a few years have one; no typical season to show
16°F No such night in a typical year (NOAA publishes no dates)
Chance of at least one night at or below 32°F in the month (NOAA MLY-TMIN-PRBOCC-LSTH032).
JanFebMarAprMayJunJulAugSepOctNovDec
93%75%44%0%0%0%0%0%0%2%56%88%

Nearby and similar places

Of the places on this site, the closest to San Antonio by station distance are Austin, TX at 69 mi (111 km), Houston, TX at 190 mi (305 km) and Dallas, TX at 247 mi (398 km).

Among places whose winter, summer and precipitation words are each within one band of San Antonio's (winter: mild, summer: hot, precipitation: moderate), the closest monthly temperature and precipitation patterns are Austin, TX, Dallas, TX and Washington, DC.

Compared with Austin, TX, San Antonio's peak-month normal high is 1.8°F (1.0°C) lower, its coldest-month mean is about the same, and its annual precipitation is 3.87 in less.

PlaceListed asStation distanceColdest mean °FWarmest high °FPrecip. in/yrSnow in/yrLast frost
San Antonio, TXthis page–52.296.032.40.2February 26
Austin, TXnearby, similar69 mi (111 km)52.297.836.20.2February 20
Houston, TXnearby190 mi (305 km)53.894.951.80.1February 13
Dallas, TXnearby, similar247 mi (398 km)46.395.837.01.6March 8
Washington, DCsimilar1,379 mi (2,220 km)37.589.641.813.7March 24

How nearby and similar places are chosen: methodology.

Source and station

The data for San Antonio come from NOAA station SAN ANTONIO INTL AP, TX US (USW00012921) at 29.5442, -98.4839, elevation 789 ft (240 m). It lies 6 mi (10 km) in a straight line from the center point of San Antonio city, the “internal point” in the US Census 2024 Gazetteer.

Each monthly normal used here rests on at least 23 years of data from 1991–2020 (NOAA's per-field year counts).

NOAA completeness flags on the monthly fields used here:

  • R: Representative: meets WMO standards for data availability for 10 or more years (missing months filled from surrounding stations).
  • S: Standard: meets WMO standards for data availability for 24 or more years.

Cite the data as:

Palecki, Michael; Durre, Imke; Applequist, Scott; Arguez, Anthony; Lawrimore, Jay (2021). U.S. Climate Normals 2020: U.S. Monthly Climate Normals (1991-2020). Station USW00012921 (SAN ANTONIO INTL AP, TX US). NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/wck8-er13. Accessed 2026-10-09.

Palecki, Michael; Durre, Imke; Applequist, Scott; Arguez, Anthony; Lawrimore, Jay (2021). U.S. Climate Normals 2020: U.S. Annual/Seasonal Climate Normals (1991-2020). Station USW00012921 (SAN ANTONIO INTL AP, TX US). NOAA National Centers for Environmental Information. Dataset. https://doi.org/10.25921/4ek7-fk11. Accessed 2026-10-09.

Files used: monthly normals CSV, annual/seasonal normals CSV (retrieved 2026-10-09). The values on this page as JSON: /us/tx/san-antonio/data.json.